thirteen - 5:56 pm on Jun 8, 2011 (gmt 0)
I was searching for a retail store that advertises on my site. The second result was the retail store's website. The third result was the retail store's ad on my site.
Was the retailer's ad on your site just a banner ad or did you write up a content webpage about the retailer?
If it was just a banner ad, did you use Google's nofollow attribute on the banner?
If a banner ad can help you move up on SERP, then you might hit on something on how to deal with Panda.